Use of rendered media to assess delays in media distribution systems

Techniques are disclosed for measuring propagation delay of a media distribution system based on content output by rendering devices. An output from an output device of the media distribution system may be captured and a token may be detected from the captured content. A timecode may be derived from the detected token. The system's propagation delay may be determined from the derived timecode and may provide a basis to analyze system delays and other processing artifacts. In this manner, propagation artifacts may be estimated between multiple rendering devices that lack controls to synchronize their operation.